Automatic control and thread cutter for sewing machines



United States Patent [72] Inventors Robert F. Miller 2,722,184 11/1955 Sweet 1 12/219(A) 128 W- Dri mp H 2,905,121 9/1959 Gerbaud l 12/219(A) Pennsylvania 17011; 2,961,591 1 1/1960 Frankel et al 1 12/219(A) Roy E. Miller, 1301 Stuart Street, 3,174,450 3/ 1965 Becker et a1 12/2|9(A)UX Mechanicsburg, Pennsylvania 17055 3,195,488 7/1965 Winberg 1 l2/219(A)UX 21] A l. N 5, 3,320,914 5/1967 Adams mmu [22] Filed April 19, 1968 P E H H H t Continuation-impart of Ser. No. 432,721, Anmary xaminer ji un er Feb. 15, 1965, abandonem ttorneys- Lmton an mton [45] Patented Sept. 15, 1970 ABSTRACT: The present attachment for sewing machines automatically positions the needle, raises and iOWelS the pres- FOR SEWNG M ACHNES sure foot, properly tensions the sewing thread, and severssaid 14 Claims, 20 Drawing Figs. sewing thread and includes a control for starting, speeding up, slowing down, or stopping the operation of the sewing [52] U.S. Cl 1 12/219, machine. The attachmem also permits the operator h f to 192/85 112/252 112/254 2 put a plurality of stitches or single stitch at a time into the. Int. Clh", orkpiece before automatically severing the thread thereof Search t t from and also provides means for automatically position. 2 66, 18 ing the needle in its top position or lowermost position as well as means for sto ing the sewing machine when the needle is [56] References cted in its up positior izpening said positioning means so that the UNITED STATES PATENTS operator can down position the needle and lift the pressure 1,850,708 3/1932 Davis 1 12/219 foot for turning the workpiece around the needle.

Patented Sept. 15, 1970 3,528,379

INVENTORS F/G. 13. EOBE'BT F. M/LLEE,

BOY 5. 04/4452,

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Patented Sept. 15, 1970 I 3,528,379

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AUTOMATIC CONTROL AND THREAD CUTTER FOR SEWING MACHINES The principal object of the present invention is to provide apparatus attachable to conventional sewing machines which apparatus while under the control of an operator, will automatically position the needle, raise and lower the presser foot, properly tension the sewing thread, and sever said sewing thread and including a control for starting, speeding up, slowing down or stopping the operation of the sewing machine.

A further important object of the invention is to provide means for modifying conventional sewing machines by the addition of reliable equipment which results in faster and simpler sewing operations and automatically positions the sewing needle and cuts the thread giving the operator the choice of putting many stitches or one single stitch in at a time into the work piece before automatically severing the thread therefrom.

Another important object is to provide means for automati-- cally positioning the needle bar with the needle at its top position or at its lowermost position and with means for stopping the sewing machine when the needle is in its up position breaking an electrical circuit connected to said positioning means whereupon the operator can energize said electrical circuit for down-positioning said needle bar and lifting the presser foot allowing the operator to turn the work piece around the needle.

A further object of the invention is to provide means for automatically and properly cutting the sewing thread betweeen the thread handling system and the work piece when each sewing step of the work piece is completed.

Further objects of the invention will be in part obvious and in part pointed out in the following detailed description of the accompanying drawings in which:

FIG. 1 is a front perspective view of a conventional sewing machine with the apparatus of the present invention connected thereto;

FIG. 2 is an enlarged perspective view of the needle bar carrying end of a sewing machine arm modified according to the present invention;

FIG. 3 is an enlarged front elevation of a part of a sewing machine in accordance with the present invention with elements removed to show the sewing machine drive;

FIG. 4 is an end view taken from the right of FIG. 3;

FIG. 5 is an enlarged sectional view taken on line 5-5 of FIG. 3;

FIG. 6 is a cross-sectional view taken on line 6-6 of FIG. 3

and laterally of the sewing machine bed showing the positioning cylinder of the present apparatus;

FIG. 7 is a greatly enlarged detail view of the needle positioning control with its cap removed;

FIG. 7a is an exploded perspective view of the synchronizer valve bracket and roller and handwheel;

FIG. 8 is a greatly enlarged cross-sectional view taken on line 8-8 of FIG. 6;

FIG. 9 is an end view of the slip clutch partially shown in FIG. 8;

FIG. 10 is an enlarged top view of the sewing thread cut-off;

FIG. 11 is a cross-sectional view taken on line ll'-ll of FIG. 10;

FIG. 12 is a cross-sectional view taken on line 12-12 of FIG. 11;

FIG. 12a is an end view of the thread cut-off tubes;

FIG. 13 is a greatly enlarged sectional view taken on line 13- -13 of FIG. 2;

FIG. 14 is a schematic diagram of the pneumatic and electrical system of the present apparatus;

FIG. 15 is a partial cross-sectional view taken on line 15- I5 of FIG. 4 showing the rear of the sewing machine and the presser foot controls;

FIG. 16 is a wiring diagram of the apparatus when the needle is up and presser foot raised;

FIG. 17 is a wiring diagram of the apparatus when the needle is down; and

FIG. 18 is an enlarged view of the knee switch forming part of the present apparatus.

Referring now more particularly to the accompanying drawings in which likeand corresponding parts are designated by similar reference characters, LA and LB designate right and standard legs and LC and LD the left hand standard legs. E is a rod extending between and connected to said standards with a treadle F having a tube G rotatably mounted on rod E.

H is a sewing machine bed supported by said standards while I is an upright mounted on said bed and having cross-arm .I supporting rod K on which. is rotatably mounted a spool L of thread M. Guide arm N is also mounted on upright I and has eye 0 through which thread M passes to pin P on the cantilever arm R of a conventional sewing machine generally designated Q. Said sewing machine slideably supports needle bar S with needle T and presser foot U.

Said sewing machine has a drive shaft hand wheel V around which extends drive belt W. X is the bed plate of the sewing machine and AA a bobbin.

The above elements A to. AA inclusive are conventional structures for sewing machines and supporting structure therefor.

Link 1 is pivotally connected at one end to bearing 2 carried by treadle F and pivotally connectedby stub axle 3 to one end of a second link 4.

Link 4 has an arm 5 fixedly connected thereto and a bent.

example, be a Singer Electric Transmitter series 552 or 553' produced by The Elizabethport F, N..l.

Said motor, clutch and brake l4 hereinafter referred to as a transmitter, is adjustably fastened to the bottom of bed H by any conventional means such as bolts or the like (not shown). A finger l2 fixedly mounted on said member 14 pivotally supports arm 11 and the other bent end of link 4 by means of a stub axle 12a.

Said transmitter 14 has a slideable drive shaft 14a extending therefrom through. control yoke 13a pivotally connected by pins 13 to arm 11. Axial movement of yoke 13a axially moves drive shaft 14a due to stops (not shown) on said drive shaft for engaging or disengaging said drive shaft through a mechanism (not shown),in transmitter 14 with the electric motor through the clutch or brake in transmitter 14.

A pulley 15 is fixedly connected to shaft 14a as is a second pulley 16. Drive'belt'W extends around pulley 15 while drive belt 17 extends around pulley 16.

A plate 18 is fixedly connected to bed H and extends normal thereto. Said plate has a slot 19 through which is adjustably mounted the shafts20a= rotatably supporting a pulley 20 by means of a nut (not shown) on said pulley shaft on the opposite side of plate 18 to said pulley 16. Further pulleys 21 and 21a are rotatably mounted on plate 18.

Piston .rod 23v .of pneumatic cylinder 24. has .screws 22 around which the ends of belt 17. are fastened while said belt extends around pulleys 20, Hand 21a. Cylinder 24 has tubes 25 and 26 connectedto the ends thereof for the operation of said piston rod.

Brake cylinder 9 has tubes 26 and 27 connected to the ends thereof forthe control of piston rod 8 while solenoid valve 10 has a tube 28 for the-admission of air under pressure into the head of brake cylinder.9 asdetermined by solenoid valve 10.

Singer Manufacturing Company,

A pneumatic speed control 29 has an air line tube 30 connected to the bottom thereof while the top is connected to a presser foot lift cylinder 31 operating a piston rod 31a whose connection to presser foot U will be explained hereinafter.

An angle rod 32 has a knee plate 34A attached thereto by clamp 34. Said angle rod is pivotally connected by stub axle 33 to transmitter 14 and is also fixedly connected by welding or the like to cylinder 31 for raising the same.

A micro-switch MS 01 is fixedly mounted on transmitter 14 with its control positioned for being pushed by link 4 when the same is raised. A second micro-switch MS 02 is carried by link 4 and has its control positioned for being pushed against member 14 when link 4 is raised.

A make and break electrical switch 35 for the electrical circuit is housed in box 36 attached to bed H.

A bobbin winder is shown at 37 in FIG. 4 bearing against belt W.

A cylindrical housing 38 has an extension V of the sewing machine drive shaft rotatably extending through an axial bore of said housing, while cam 39 therein is fixedly connected to said extension V and thus to hand wheel V for rotation therewith. Said cam is circular except for radial point 40. A rocker 41 of electrical insulating material is pivotally mounted on pin 42 carried by housing 38 and carries a spring contact 44. A point 45 is fixedly mounted on housing 38 for normally being engaged by contact 44 due to spring 43 connected to housing 38 and rocker 41.

A second insulating rocker 46 is pivotally mounted on pin 47 carried by housing 38 and said rocker 46 is held against cam 39 by spring 48 attached to said rocker and housing 38. Said rocker carries a spring contact 49 normally bearing against point 50 fixedly connected to housing 38.

Points 45 and 50 are positioned 180 apart and so that cam 39 opens one contact 44 or 49 from its respective point 45 or 50 when the needle bar S is all the way up and the other of said contacts when the needle bar is all the way down. A cable 51 is connected to points 45 and 50.

Pulley 16 contains a slip clutch provided by hub 16a keyed by key 54 in slot 55 to shaft 140 and positioned within axial bore 52 of said pulley. A plurality of rollers 53 are positioned between hub 16a and said pulley 16 and hub 16a has a series of spaced apart radial teeth 56 and inwardly slanting curved peripheral portions 57 each extending between a pair of consecutive teeth 56 with a roller 53 positioned on each portion 57 for rolling movement between the pair of teeth 56 terminating said portion 57. A washer 58 is positioned against the outer end of said hub 16a and said pulley 16 while a ring nut 59 in threaded engagement with threads 60 on shaft 14a retains washer 58 in place. Hub 16a further has an annular flange 61 which provides a guide for the inner end of said pulley 16. Thus hub 16a, pulley l6, washer 58 and flange 61 provide a cage for rollers 53.

As best shown in FIGS. 2 and 5, the end face 62 of said sewing machine arm R has a recess 63 in which is mounted microswitch 64 alongside a pair of micro-switches 65 and 65a. Micro-switch 64 has an extended control bar 66 spaced from extended control bars 67 and 67a of micro-switches 65 and 65a, respectively.

A block 68 is fastened to the end of a piston rod 81 by screws 69 and has a lateral finger 70 extending between control bar 66 and control bars 67 and 67a.

Sewing-machine arm end 62 has recesses 71 in the back, 72 in the front and 73 in the bottom leading to recess 63 and a cover plate 74 in FIG. 4, for said arm end 62.

A U-shaped guide 75 is mounted on the front of arm end 62 while rollers 76, 77, and 78 extend across opening 72.

Pigtails 79 and 80 are connected to block 68 and positioned for extending through opening 72 between rollers 76, 77 and 78.

Said piston rod 81 extends through opening 71 into a pneumatic cylinder 82 fastened to the rear side of arm end 62 and which cylinder has a tube 82a connected to the inner end thereof, a screw 83 whose threads are in threaded engagement with cylinder 82 and lock nut 84b with screw 83 extending into cylinder 84 for limiting the movement of piston rod 81 towards the outer end of said cylinder. A coil spring 85 encircles piston rod 81 between block 68 and said cylinder.

A pin 86 attached to arm end 62 in opening 73 pivotally supports bent lever 87 extending through said opening 73. A sleeve 88 of a thread clamp is in threaded engagement with arm end 62 and has coil spring 89 on the inner end thereof while valve shaped stem 90 slideably extends through said sleeve 88 and coil spring 89 with its flanged inner end against arm 87 and retaining coil spring 89 against sleeve 88. Said sleeve has a valve seat shaped recess 91 in the outer end thereof for at times receiving the outer end of valve stem 90.

A thread guide 93 attached to arm R has bent spring arms 92 adjustably held by bolt 94 in threaded engagement with said arm R.

An automatic thread tension release consists of a cylinder 95, a piston 95a in said cylinder, a threaded rod 95b fixedly connected at one end to arm R, a disc 95c slideably mounted on rod 95b, a second disc 95d fixedly connected to arm R, tube 96 connected to the outer end of cylinder 95, nut 97 in threaded engagement with rod 95b and a coil spring 98 surrounding rod 95b between said nut and the inturn end 95a of said cylinder 95. Rod 95b is split at its outer end for receiving pin 95F extending through a slot in the extension of said piston and into cylinder 95 for preventing the turning of said cylinder.

A thread cut-off is best shown in FIGS. 5 and 10 to 12a, inclusive. Said thread cut-off has a pair of superposed curved tubes 99 and 100 with a steel band 101 extending in tube 99 and a second steel band 102 extending in tube 100. Tube 99 has an upturned lip 103 at the free outer end thereof and an opening 104 extending therethrough above the free outer end of tube 100 and bobbin AA of the sewing machine Q. Said tube free ends are positioned just below the needle opening for bed X of the sewing machine.

A cylinder head 105 is positioned below a bottom portion 106 of the sewing machine in threaded engagement with a cylinder tube 108. A cylinder cap 107 also is in threaded engagement with cylinder tube 108, but positioned above bottom portion 106 of the sewing machine and has tubes 99 and 100 integral therewith and openings for bands 101 and 102 which bands are also integral with piston rod 109, slideable in tube 108 and extending through head 105. A coil spring 110 surrounds piston rod 109 between head 105 and nut 111 in threaded engagement with said piston rod. A tube 112 is connected to and through head 105.

As shown in FIG. 10 the sewing machine bottom member 106 has a semicircular recess 116 while a block also has a semi-circular recess 113 for holding tube 108 therebetween. Bolts 115a and 115k extend through block 115 and screw into bottom member 106 holding said block therein.

Micro-switch 117, FIGS. 1 and 18, is mounted on standard leg LC with its control button 117a facing a knee plate 118 pivotally mounted on rod 119a pivotally connected by pivot 119 to bed H. Plate 118 has an arm 118a attached thereto while rod 119a has a pin 11912 extending therefrom and collar 119v with coil spring 119d whose ends engage said plate and collar.

Plate 118 as shown in FIG. 18 is pivoted inwardly depressing control button 1 17a and is held in that position by arm 118a engaging pin 11%. An operator by manually pushing said plate can disengage arm 118 from pin 11% whereupon plate 118 will pivot out and move upwardly through spring 119d releasing control button 117a. Thus plate 118 can be held against control button 117a whenever 'the operator requires the same.

A double source of electrical current is indicated by double wall socket 120 with plugs 121 and 122 each plugged in one of the sockets. Plug 121 is connected to switch 35 while plug 122 is connected to the electric motor, clutch and brake 14 for energizing the same.

An air tube 123 is connected to a source of air under pressure (not shown) and to and through box 124, FIG. 3, which houses solenoid valves A, B, C, D and 140 and air speed regulators 125, 126 and 127 and tube 128, FIG. 14, connected to said tube 123.

Referring to FIG. showing the back of sewing machine Q, piston rod 31a, see FIG. 3, extends through bed H and is loosely connected to lever 129 pivoted on arm R by a pin 130. A pair of nuts 131 in threaded engagement with threads 132 of rod 31a are on each side of lever 129. Said lever 129 is pivotally connected by pin 133 to link 134 while link 134 is pivotally connected by pin 135 to the conventional presser foot raising and lowering lever 136 of the sewing machine.

Mounted on the top of the sewing machine Q, adjacent to the handwheel V is a bracket 137, having a downwardly extending leg 138. Secured to said leg 138, is an air cylinder 139 having a piston rod 141 extending therefrom in the direction of the handwheel V. A pin 142 pivotally supports arm 143 on said bracket so that arm 143 extends betweeen leg 138 and handwheel V. The free end of arm 143 has a roller 144 rotatably mounted thereon which is adapted to move into notch 145 on the handwheel V when said piston rod 141 is extended due to air being forced into cylinder 139 through tube 166 which is connected to control valve 140. The notch 145 is located in such a position on handwheel V so that the needle bar 8 of the sewing machine will be in top dead center position when said roller 144 is engaged in notch 145.

Referring to FIG. 7a, notch 145 is in the periphery of a ring 146 held by set screws 147 on handwheel V modified to receive the same. Housing 38 has an extension 148 integral therewith and link 149 attached to said extension. One end of spring 150 is attached to link 149 and its other end to arm 152 while stop 151 extends from extension 148 to arm 152 limiting the contraction of spring 150.

Screws 153 extend through openings 154 in bracket 137 into the top of said sewing machine for retaining said bracket thereon. Screw 155 extends through washer 156 and spring 157 into threaded opening'l55a in said bracket.

The threaded end of cylinder 139 has nut 158 and washer 159 thereon andextends into threadedopening 160 in said bracket for being supported thereby.

Set screw 161 is in threaded opening 162 for engaging the end of pin 142 in opening 174 for retaining said pin therein.

Elbow 163 is in threaded engagement with threaded opening 164 in cylinder 139 while eyelet 165a and sleeve 165 are in said elbow and nut 164a is in threaded engagement with said elbow retaining tube 166 to said elbow.

Clamp 167 for wire 51 and arm 152 are attached to bracket leg 138 by screws 168 passing through openings 169 in arm 152 into threaded openings 169a in leg 138. Clamp 170 for wire 51 has screw 171 extending through washer 172, clamp 170 and into threaded opening 172a in arm 152.

Arm 143 has a lateral opening 173 through which extends pin 142 and a roller pin 175 extending through arm openings 176 and roller 144 rotatably retaining said roller partially in arm recess 174. A retaining ring'177 fits the end of roller pin 175 for holding the same in place.

FIG. 14 is a combination electrical and pneumatic sche matic diagram showing the electrical as well as compressed air connections between the elements hereinbefore referred to. In this diagram there is also included relays R and R, whose operation.will be hereinafter described.

FIG. 16 is a view of the electrical circuit wiring diagram of FIG. 14 when needle T is in its up position and presser foot U raised, but with synchronizer valve 140 omitted. When the operator releases his heeling action on treadle F, the presser foot U will drop.

FIG. 17 is a view of the electrical circuit wiring diagram of FIG. 14 when needle T is in its down position;

In the operation of a sewing machine Q, modified according to the present invention, thread M is passed to post P, through guide Y, betweeen disc 95c and disc 9511, through thread tension lever Z, through eye 75 and pigtails 80, between valve stem 90 and seat 91, through the eye of needle T and double looped through bed X and opening 104 in tube 99. The thread from bobbin AA also passes through opening 104 in tube 99 and bed X so that the end of thread M and the bobbin thread are above bed X.

If the operator presses forward on the treadle F, the sewing machine will be operated in the normal manner. That is, pressing hard forwardly and down on said treadle causes the sewing machine to run at top speed while letting up on said treadle causes the sewing machine to slow down and taking the foot off the treadle completely stops the sewing machine stopping the sewing action.

When the operator feeds the work piece across bed X beneath needle T and presser foot U and heels down on treadle F raising link 1 pressing link 4 against micro-switches MS #1 amd MS #2, FIG. 3, tripping said microswitches, microswitch MS #1 supplies current to points 45 and 50. Cam 40 rotates at the speed of the sewing machine and alternately opens and closes contacts 44 and 49 with points 45 and 50 respectively of the needle positioner. Contact 44 and point 45 control the up position of needle T while contact 49 and point 50 control the down position of needle T. By energizing point 45 and contact 44, the sewing machine will stop with needle T all the way up while energizing point 50 and contact 49, the sewing machine will stop with needle T all the way down. Thus if point 45 and contact 44 are energized, the sewing machine can be made to stop with needle T up, since cam 40 will open contact 44 from point 45 when said cam rotates around to that position breaking the electrical circuit.

If contact 49 engages point 50 they will supply current to the solenoid valves D and 10 and relay R Said solenoid valves D and 10 pass compressed air to the positioning cylinder 24 by tube 25 and the brake cylinder 9 by tube 9a extending piston rod 23 which pulls cable 17 rotating pulley 16 in a direction which moves rollers 53 against teeth 56 of the slip clutch of FIGS. 8 and 9 against pulley 16 causing said clutch to grab and thus rotate shaft 140 rotating in transmitter 14 and also pulley 15, belt W and hand wheel V causing cam 40to rotate until it opens contact 49 from point 50. At the same time the needle positioner, solenoid valves and relay R are de-energized shifting piston rod 23 into cylinder 24 and putting brake cylinder 9 in its brake position stopping hand wheel V, opening the contacts 44 and 49, thus the brake of transmitter 14 is released and reapplied very quickly while contact 49 and point 50 are open. Needle T is thus now positioned all the way down through the work piece. Also at the same time when relay R was de-energized the normally closed contacts in said relay supplied current to solenoid valve C passing air to cylinder 31 liftingpresser foot Sthrough rod 31a, lever 129, links 134 and of FIG. 15, which allows the operator to turn the work piece around the needle. Piston rod 23 returns into cylinder 24 through the slip action of the clutch in pulley 16.

Said slip clutch of pulley 16 is necessary to prevent the reverse rotation. of the shaft of hand wheel V which would cause needle T to come out of the work piece and said slip clutch allows piston rod 23 to return into cylinder 24, its starting point, without reversingthe rotation of hand wheel V.

With the operator still heeling backwards on treadle F, he can push knee plate 118 againstmicro-switch 117, closing the same and energizing contact 44 and point 45, solenoid valves D and 10 and relay R thus the brake of transmitter 14 is released and piston rod 23 pulls pulley 15 and the slip, clutch of pulley 15.around sothat needle T is moved up. The brake of transmitter 14 is then quickly reapplied and solenoid valves A and B actuated releasing disc 95c from disc 95d releasing thread M, moving pigtails 79 and 80 to the left of FIG. 5 drawing thread M in recess 63, raising piston rod 109 so that band 102 gives thread M and the bobbin thread a U-shaped bend as shown in FIG. 5 and then band 101 severs the threads from the work piece automatically. With micro-switch 117 set in the needle up position, current is sent directly to valve which will open allowingair to pass throughtube 166-to cylinder 139. As the handwheel U is rotated by the positioning cylinder 24, roller 144 will ride on ring 146 until it engages notch 145 at which time the needle T will be in top dead center position in which position the normal thread tensions of the sewing machine are released to allow the thread M to be drawn freely from the supply by the thread puller. Presser foot U remains in its up position until the operator lets up on his heel on treadle F, at which time said presser foot drops. When piston rod 81 goes into cylinder 82 as far as allowed by screw 83, finger 70 activates micro-switch 64 which energizes relay R breaking the return line of the synchronizer solenoid 140 to return it to its normal position. Relay R is locked in the down position by current from micro-switch MS #2 and starts the return of piston rod 81 to its position in FIG. 5 and at the same time activates piston rod 109 and bands 101 and 102. When piston rod 81 reaches its position of FIG. 5 it operates micro-switches 65 and 65a, and piston rod 109 is lowered. Releasing microswitch 117, the foot lift solenoid valve C is energized lifting presser foot U.

With the operator still pressing down with his heel on treadle F and holding micro-switch 117 closed and then releasing said micro-switch 117 before cam 40 reaches and opens contact 44, piston rod 23 will turn transmitter shaft 14a and pulley 15 around to the down position of needle T before said needle stops and presser foot U is raised. This puts one stitch in the work piece at a time. Such operation requires a quick tap on knee plate 118 with the operators knee, while to cut the thread from the work piece as hereinbefore described requires micro-switch 117 to be held closed somewhat longer.

For greater speed in cutting the thread M from the work piece, knee plate 118 can be locked against micro-switch 117 by pushing said knee plate all the way down, see FIG. 18, rotating said knee plate against control button 117a and raising said knee plate so that the hook on arm 118a engages pin 11%. Then the operator can at any time heel backward on treadle F which activates piston rod 109 and thus bands 101 and 102, positioning the needle up, releases the tension on the thread, pulls the thread, trims the work piece and raises the presser foot. As long as the treadle is heeled, the presser foot remains up permitting the removal of the finished work piece and the introduction of a new work piece. However, said micro-switch must be released and opened by manually moving arm 118a from pin 119i; and said knee plate from control button 117a before the needle T down positioning elements as hereinbefore described can be operated.

When the operator presses forwardly or toes down hard on treadle F the sewing machine Q operates in the normal manner at top speed. Letting up on treadle F causes the sewing machine to slow down and taking the foot off of the treadle F completely stops the sewing machine.

Lever 87 is positioned between valve stem 90 and block 68 so that movement of said block to the entire right of FIG. 5 pushes said valve stem to the right against spring 89 releasing the thread M. However, when block 68 is to the left of FIG. 5, spring 89 returns said valve stem against seat 91 against thread M. At any time the operator can manually pivot lever 87 to move either valve stem 90 or block 68 if desired.

Solenoid valves A, B, C, D and are conventional electrically operated valves such as manufactured by the Automatic Switch Co., Florham Park, N.J., Catalog Nos. GY8314A33 and GY8314A51. Similarly regulators 125, 126, 29, 24a and 127 are conventional air flow control valves.

The present invention is capable of considerable modification and such changes thereto as come within the scope of the appended claims is deemed a part thereof.

We claim:

1. In a sewing machine having a rotary drive shaft, stitching instrumentalities, and presser foot, a control therefor comprising a clutch and brake unit, an electrically operated motor connected to said clutch and brake unit, a drive shaft rotatably and slideably mounted therein for operating said unit, means operatively connecting said drive shaft to the sewing machine drive shaft, a cam fixedly connected to said sewing machine drive shaft, normally closed make and break points so positioned to be separately opened by said cam, pneumatic means for turning said cam to a position for opening one of said points at a time, a pneumatically operated thread cut-off, a pneumatically operated presser foot lift, a pneumatically operated thread tensioning and releasing means, a pneumatic brake cylinder having a piston rod operatively connected to said slideable drive shaft for moving the same to its clutch releasing position and its brake engaging position, a foot operated linkage system connected to said piston rod, a source of air under pressure, electrically operated solenoid air valves connected to said source of air and one of said valves connected to each of said cam turning pneumatic means, pneumatically operated thread cut off, pneumatically operated presser foot lift, pneumatically operated thread tensioning and releasing means and pneumatic cylinder, a source of electrical current, a first pair of normally open make and break switches so positioned to be closed by said linkage system, a pair of relays, a manually operable make and break electrical switch, a second pair of make and break switches mounted on said sewing machine and so positioned to be operated one at a time by said thread tensioning and releasing means, one of said first pair of switches being electrically connected to said points, said manually operable switch, said second pair of switches and the other of said first pair of switches, one of said relays being electrically connected to said other of said first pair of switches, one of said second pair of switches, the solenoid valves for said pneumatic brake cylinder and said pneumatically operated thread cut-off, said pneumatically operated thread tensioning and releasing means, one of said points, said manually operable switch and said other relay, said other relay being electrically connected to said manually operable switch, the solenoid valves for said pneumatic means for turning said cam, said pneumatically operated thread tensioning and releasing means and said pneumatically operated presser foot lift, a slip clutch in said pneumatic means for turning said cam and said manually operable switch being electrically connected to the other of said points and sources of electrical current connected to said electrically operated motor and said first pair of switches and said one of said relays.

2. In a sewing machine as claimed in claim 1 wherein said points are fixedly connected to said sewing machine and positioned apart.

3. In a sewing machine as claimed in claim 1 wherein said pneumatic means for turning said cam consists of a fixed pneumatic cylinder having opposite end openings for receiving air therein at one end from its solenoid valve and at its other end from said brake cylinder, a piston rod slideably mounted in said fixed cylinder, a series of rotatably mounted pulleys, a pulley mounted on said clutch and brake unit drive shaft and connected thereto by said slip clutch and a belt extending around said pulley and having its ends connected to said piston rod.

4. In a sewing machine as claimed in claim 1 wherein said foot operated linkage system consists of a pivotally mounted treadle, a link pivotally connected to said treadle, a second link pivotally connected at one end to said first link and at its other end to said clutch and brake unit, an arm fixedly carried by said second link and pivotally connected to the piston rod of said brake cylinder.

5. In a sewing machine as claimed in claim 1 wherein said brake cylinder is pivotally mounted and has air openings at the opposite ends thereof for receiving air therein at one end from its solenoid valve and said pneumatic means for moving said drive shaft in one direction and at its other end from the solenoid valve for said pneumatic means for moving said drive shaft in an opposite direction.

6. In a sewing machine as claimed in claim 1 wherein said pneumatically operated thread tensioning and releasing means consists of a pneumatic cylinder, a piston rod connected to said sewing machine, a piston carried by said rod slideably mounted in said cylinder, said piston rod having asplit outer end, a rod carried by said cylinder extending through said rod split end, a cap carried by said cylinder, a disc fixedly mounted on said sewing machine and facing said cylinder cap for receiving the sewing machine thread therebetween, a spring tending to move said cap to said disc, said cylinder having an air inlet connected to one of said solenoid valves, pneumatic means connected to said one of said solenoid valves for pulling said thread when said cap is moved from said disc, a valve seat fixedly mounted on said sewing machine, a valve stem slideably mounted in said valve seat for receiving said thread therebetween, resilient means tending to retain said valve stem against said valve seat and means operable by said thread pulling pneumatic means for at times moving said valve stem from said valve seat.

7. In a sewing machine as claimed in claim 1 wherein said pneumatically operated thread tensioning and releasing means include a pneumatic cylinder having an air inlet at one end connected to one of said solenoid valves and fixedly connected to said sewing machine, a piston rod slideably extending from said cylinder, a block carried by said piston rod having a finger for operating the second pair of switches each at an opposite end of the stroke of said piston rod, and pigtails carried by said block for receiving the sewing machine thread therethrough for being pulled upon movement of said piston rod.

8. In a sewing machine as claimed in claim 1 wherein said pneumatically operated thread cut-off consists of a pneumatic cylinder having an air inlet at one end connected to one of said solenoid valves, a piston rod slideably mounted in said cylinder, a pair of curved tubes with one tube having a thread opening therethrough above the outer end of the other of said tubes, and both said tubes being fixedly mounted on said cylinder, a pair of steel bands each slideably mounted in one of said tubes and both bands being fixedly connected to said piston rod and resilient means tending to retain said piston rod towards said cylinder air inlet.

9, In a sewing machine as claimed in claim 1 wherein said pneumatically operated presser foot lift consists of a cylinder having an air inlet connected to one of said solenoid valves, a piston rod slideably extending from said cylinder, a lever pivotally mounted on said sewing machine and operatively connected at one end to said piston rod, and links pivotally connecting said lever to said presser foot for raising the same at times.

10. In a sewing machine as claimed in claim 1 and having a pneumatic cylinder mounted on said sewing machine, a pivotally supported roller, said pneumatic cylinder having a piston rod engaging said roller, a collar mounted on said sewing machine drive shaft and having a notch therein adapted to be engaged by said roller, an electrically operated solenoid air valve connected to a source of air and said cylinder, said solenoid valve being actuated to supply air to said cylinder when it is desired to position the stitching instrumentalities out of the work thereby causing said roller to engage the notch and assure the positioning of the shaft.

11, In a sewing machine having a rotary drive shaft and reciprocating needle operatively connected to said drive shaft, a needle positioner comprising a cam fixedly connected to said drive shaft, a casing fixedly connected to said sewing machine, a pair of points fixedly connected to said casing, spring contacts connected to said casing with each contact positioned for normally engaging one of said points and being separated therefrom by said cam upon rotation of said drive shaft, electrically operated means including driving motor means for rotating said drive shaft, pneumatic means for positioning said drive shaft respectively with said needle all the way up or all the way down, pneumatic means for at times stopping said electrically operated means for rotating said drive shaft, a source of air under pressure, solenoid valves connected to said source of air and both said pneumatic means for supplying air thereto at times, a source of electrical current connected to said points and an electrical circuit connected between said contacts and said solenoid valves whereby said contacts at times operate said solenoid valves for selectively stopping said drive shaft with said needle up or down.

12. In a sewing machine as claimed in claim ll wherein said ggwi igmachine has a pneumatic cylinder mounted thereon, a

pivotally supported roller, said pneumatic cylinder having a piston rod engaging said roller, a collar mounted on said sewing machine drive shaft and having a notch therein adapted to be engaged by said roller, an electrically operated solenoid air valve connected to a source of air and said cylinder, said solenoid valve being actuated to supply air to said cylinder when it is desired to position the stitching instrumentalities out of the work thereby causing said roller to engage the notch and assure the positioning of the shaft.

13. In a sewing machine having a rotary drive shaft and reciprocating needle operatively connected thereto, a needle positioner comprising a pneumatic cylinder having air inlets at opposite ends thereof, a piston rod slideably extending from said cylinder, a pulley, a flexible member extending around said pulley and connected at its ends to said piston rod, a rotatable shaft, a slip clutch connecting said pulley to said rotatable shaft, means operatively connecting said drive shaft and said rotatable shaft, a source of air under pressure, solenoid air valves connected to said source of air and one of said valves being connected to each of said air inlets of said cylinder, and electrical means operatively connected to said solenoids and said drive shaft whereby said drive shaft operates one of said solenoid air valves at a time respectively positioning said needle up or down. N 7

14. In a sewing machine having a rotary drive shaft, stitching instrumentalities and a presser foot, a control therefor comprising a clutch and brake unit, an electrically operated motor connected to said clutch and brake unit, means connecting said clutch and brake unit to the sewing machine drive shaft, auxiliary means connected to said connecting means for rotating said sewing machine drive shaft when said electrically operated motor is disconnected therefrom, a control circuit for said clutch and brake unit and said auxiliary means for stopping said stitching instrumentalities selectively in or out of the work being sewn, and means mounted on said sewing machine for accurately positioning the stitching instrumentalities in their remotest position from the work when it is desired to stop the sewing machine with the stitching instrumentalities out of the work comprising a pneumatic cylinder mounted on said sewing machine, a collar mounted on said sewing machine drive shaft, said collar having a notch therein, an arm pivotally mounted on the sewing machine, a roller mounted on said arm for engagement with said notch and a piston rod extending from said cylinder into engagement with said am for forcing said roller into said notch when said control circuit actuates said cylinder.

UNITED STATES PATENT OFFICE Certificate of Correction atent No. 3,528,379 September 15, 1970 Robert F. Miller et 91. It is certified that error appears in the above-identified patent and that said Letters F'atent are hereby corrected as shown below.

The figure on the title page should appear as shown below:

Signed and sealed this 20th day of April 1971.

Attest:

EDWARD M. Fmrozmn, JR. WILLIAM E. Scnm'mR, JR. G'ommz'asiomr of Patents.

Atteating Officer. 

